FILTER FOR THIRD-ORDER PHASE-LOCKED LOOPS

摘要

Filters for third-order phase-locked loops used in receivers to acquire and track carrier signals, particularly signals subject to high doppler-rate changes in frequency, are provided by employing a loop filter with an open-loop transfer function F(s) = (1 + tau 2s/1 + tau 1s) + 1/(1 + tau 1s)( delta + tau 3s) AND, FOR A GIVEN SET OF LOOP CONSTANTS, SETTING THE DAMPING FACTOR EQUAL TO UNITY.